Bearing damage, and ultimately, failure, can be caused by a variety of conditions, including improper mounting, poor lubrication, and overloading, to name a few. The mode of damage — what actually happened to the bearing as a result of detrimental conditions — is characterized by visible features, such as discoloration, wear marks, or pitting, on […]
Ball + lead + roller screws
Exlar GTX now with Hiperface DSL Stegmann absolute encoders
Curtiss-Wright Corporation’s Industrial Division announced that its Exlar facility, located in Chanhassen, MN, has added Hiperface DSL Stegmann absolute encoders as a part of their available Rockwell Automation feedback options. The GTX series joined the Exlar TTX, Tritex II, GSX, FTX, and K series Encompass product families in 2018. As an Encompass Partner, Curtiss-Wright and Rockwell […]
Using software for designing and sizing motion-control systems
Today servomotors abound. Thankfully the art of using speed, torque, and inertia to select from these servomotor offerings for specific applications has become quite automated. By Sixto Moralez • Regional motion engineer | Yaskawa America Inc. Drives & Motion Div. Now, certain sizing and selecting software only requires that design engineers enter a minimum of […]
Why use linear guides and ball screws with ball chains?
One of the differences between radial ball bearings and recirculating ball linear guides has historically been that radial bearings typically use a cage to separate the balls and control their movement, whereas profiled rail guides did not. But in the early 2000’s, manufacturers of profiled rail bearings began introducing versions with ball cages (also referred […]
Update on roller-screw actuator design and applications (with video and image galleries)
Roller screws are also called planetary roller screws or sometimes satellite roller screws for how their nut-encased rollers orbit the drive-shaft axis during operation. These mechanical rotary-to-linear devices work in an increasing number of electromechanical actuators. Satellite roller-screw geometry includes far more internal contact between load-bearing subcomponents than their ballscrew cousins, and that boosts rigidity […]
Mechanical properties of materials: Shafts in torsion
Power transmission shafts — on motors and gearboxes, for example — are subjected to torque loads that result in torsion, or twisting of the shaft about its axis. Similar to structures under tension or compression, two important mechanical properties of shafts under torque loads are shear stress and shear strain. Stress is a material’s resistance […]
Ball screw standards: What you need to know about DIN, ISO, and JIS
If you’re involved in ball screw sizing or selection, you’ve probably noticed that there are several different standards that govern various aspects of ball screw design, from lead accuracy and load capacity to ball nut tolerances and rigidity. Fortunately, in many cases, these standards are in harmony and provide the same (or virtually equivalent) specifications. […]
Tribology basics for linear bearings
Tribology is the study and application of the principles of friction, lubrication, and wear between two surfaces in relative motion. In linear bearing systems, those two surfaces are the bearing element and the guide raceway. Friction and wear The term “wear” generally refers to deterioration, but when discussing tribology principles in relation to bearings, it refers […]
How to specify linear motion components for vacuum applications
Vacuum applications are common in the manufacturing of semiconductors, liquid crystal and plasma displays, fiber optics, and aerospace components, where linear motion systems are used for the positioning, handling, and alignment of critical equipment. Although vacuum applications are often likened to cleanroom applications, in the category of “special environments,” there is a critical difference between […]
THK to show low-inertia ballscrew-spline BNS-V during IMTS
In two weeks, IMTS visitors will be able to see THK’s ballscrew-spline BNS-V at booth #134514. Featuring an exceptionally compact and lightweight structure, the low-inertia BNS-V enables quick starts and stops during high-speed operation. The BNS-V is a stroke-rotary unit with ball screw grooves and a ball spline groove that cross one another on a […]
